EVALUATION OF REAL TIME – PCR AS A TOOL FOR DIAGNOSIS OF SCHISTOSOMA MANSONI IN A LOW TRANSMISSION AREA, MONTES CLAROS, MINAS GERAIS, BRAZIL.

Abstract

The conventional diagnosis of schistosomiasis mansoni is realized by parasitological approaches, especially by Kato‐Katz technique, however in situations of low parasite burden this technique loses sensitivity. Thus, the aim of this study was to evaluate the molecular assay, the Real Time‐PCR for diagnosis and assessment of cure of schistosomiasis. A population‐based study was carried out with 148 inhabitants from a low transmission area in Brazil. To establish the infection rate one stool sample was analyzed by the parasitological techniques Kato‐Katz (24 slides) and the Saline Gradient (1000mg). The Real Time‐PCR was performed using 1000 mg of the same stool sample. To establish the cure rate, the positive individuals were followed‐up 30, 90 and 180 days after the treatment. The prevalence rate obtained by the two parasitological techniques was 31.75% (47/148). The positivity rate was 29.0% (43/148) by Saline Gradient technique, 20.9% (31/148) by 24 K‐K slides, 30.4% (45/148) by Real Time‐PCR. In order to determine the cure rate of 47 positive individuals, they were followed‐up for 6 months, and the cure rates were 100% (39/39), 91.6% (33/36) and 78.4% (29/37), 30, 90 and 180 days after treatment. For the Real Time‐PCR the same cure rates were 100% (39/39), 83.3% (30/36) and 62.1% (23/37), respectively. The results obtained by Real Time‐PCR point to development of a promising diagnostic method and could represent an important step forward to support studies on epidemiology and cure control of the disease, especially when its cost to reduce.